Connected with clients, but no remote view / control


  • I have succesfully installed Veyon Master on the Windows 10 master PC and 2 clients. Thumbnail is working properly and I can open sites, lock screens, give demo etc.

    The problem I experience is that I can't remote view or control the client computers. If I try so, it keeps "connecting", but nothing happens. Eventually the thumbnail get's the red / orange color and after 2 minutes reappears.

    i have collected some logs from client side:

    1. VeyonConfigurator.log (clientside)
    2021-04-26T11:47:24.710: [ERR] CryptoCore: failed to decrypt password!
                                                                            2021-05-10T08:31:21.755: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T09:34:08.320: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T09:40:15.148: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T10:56:27.323: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T11:04:58.834: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T11:10:40.427: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T11:24:40.668: [ERR] CryptoCore: failed to decrypt password!
    2021-05-10T11:59:41.199: [ERR] CryptoCore: failed to decrypt password!
    
    1. VeyonServer.log (clientside)
    2021-05-10T12:17:32.613: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:32.613: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:33.613: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:33.613: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:34.065: [DEBUG] ServerAuthenticationManager::processAuthenticationMessage(): state VncServerClient::AuthState::Init type RfbVeyonAuth::KeyFile host "fe80::e177:256e:f37a:d9a7%9" user "ICT SPI"
    2021-05-10T12:17:34.077: [DEBUG] ServerAuthenticationManager::processAuthenticationMessage(): state VncServerClient::AuthState::Challenge type RfbVeyonAuth::KeyFile host "fe80::e177:256e:f37a:d9a7%9" user "ICT SPI"
    2021-05-10T12:17:34.079: [DEBUG] ServerAuthenticationManager::performKeyAuthentication(): loading public key "C:\\ProgramData\\Veyon\\keys\\public\\Leerkracht\\key"
    2021-05-10T12:17:34.079: [DEBUG] ServerAuthenticationManager::performKeyAuthentication(): SUCCESS
    2021-05-10T12:17:34.080: [DEBUG] AccessControlProvider::checkAccess(): no access control method configured, allowing access.
    2021-05-10T12:17:34.080: [INFO] ComputerControlServer::showAccessControlMessage(): Access control successful for "fe80::e177:256e:f37a:d9a7%9" "ICT SPI"
    2021-05-10T12:17:56.242: [INFO] [UltraVNC] virtual void* vncSockConnectThread::run_undetached(void*) : accepted connection from 127.0.0.1
    2021-05-10T12:17:56.242: [INFO] [UltraVNC] virtual vncClientId vncServer::AddClient(VSocket*, BOOL, BOOL, int, char (*)[13], VString, VString, VCard, BOOL) : AddClient() started
    2021-05-10T12:17:56.242: [DEBUG] [UltraVNC] vncClient::vncClient() : vncClient() executing...
    2021-05-10T12:17:56.242: [DEBUG] [UltraVNC] virtual vncClientId vncServer::AddClient(VSocket*, BOOL, BOOL, int, char (*)[13], VString, VString, VCard, BOOL) : AddClient() done
    2021-05-10T12:17:56.242: [INFO] [UltraVNC] virtual void vncClientThread::run(void*) : client connected : 127.0.0.1 (2)
    2021-05-10T12:17:56.243: [INFO] [UltraVNC] virtual bool vncClientThread::InitSocket() : failed to set socket timeout(0)
    2021-05-10T12:17:56.243: [INFO] [UltraVNC] virtual BOOL vncClientThread::InitVersion() : Send protocolMsg
    2021-05-10T12:17:56.243: [INFO] [UltraVNC] virtual BOOL vncClientThread::InitVersion() : Send_OK
    2021-05-10T12:17:56.251: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.251: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.251: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.251: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.251: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.251: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.251: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.251: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.251: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.252: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.252: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.253: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    2021-05-10T12:17:56.253: [DEBUG] FeatureManager::handleFeatureMessage(): feature "FeatureControl" command 0 arguments QMap()
    2021-05-10T12:17:56.253: [DEBUG] ComputerControlServer::sendFeatureMessageReply(): QUuid("{a0a96fba-425d-414a-aaf4-352b76d7c4f3}") 0 QMap(("0", QVariant(QStringList, ("{8e997d84-ebb9-430f-8f72-d45d9821963d}"))))
    
    1. VeyonService.log (clientside)
    2021-04-26T13:25:58.807: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-04-26T14:16:09.592: [ERR] WindowsCoreFunctions: OpenProcess() 0
    2021-04-26T14:16:09.592: [ERR] VeyonServerProcess: Failed to start server!
    2021-04-29T10:00:07.197: [ERR] WtsSessionManager: called with invalid session ID
    2021-04-29T10:00:07.197: [ERR] ---
    2021-04-29T10:00:07.197: [ERR] Last message repeated 1 times
    2021-04-29T10:00:07.197: [ERR] ---
    2021-04-29T10:00:07.197: [ERR] WindowsCoreFunctions: OpenProcess() 0
    2021-04-29T10:00:07.197: [ERR] VeyonServerProcess: Failed to start server!
    2021-04-29T11:20:25.418: [WARN] VeyonServerProcess: Terminating server
    2021-04-29T11:53:17.123: [ERR] WtsSessionManager: 2
    2021-04-29T11:53:17.123: [ERR] WindowsCoreFunctions: OpenProcess() 0
    2021-04-29T11:53:17.123: [ERR] VeyonServerProcess: Failed to start server!
    2021-05-05T11:42:31.091: [ERR] WindowsCoreFunctions: OpenProcess() 0
    2021-05-05T11:42:31.091: [ERR] VeyonServerProcess: Failed to start server!
    2021-05-10T08:54:05.481: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T09:25:48.434: [ERR] WtsSessionManager: 2
    2021-05-10T09:25:48.434: [ERR] WindowsCoreFunctions: OpenProcess() 0
    2021-05-10T09:25:48.434: [ERR] VeyonServerProcess: Failed to start server!
    2021-05-10T09:37:57.127: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T10:30:36.854: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-05-10T11:08:48.618: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T11:23:22.923: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-05-10T11:31:28.548: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T11:31:29.564: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-05-10T11:34:22.268: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-05-10T11:34:55.119: [WARN] QWinEventNotifier: no event dispatcher, application shutting down? Cannot deliver event.
    2021-05-10T11:59:51.042: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T12:12:29.237: [WARN] VeyonServerProcess: Terminating server
    2021-05-10T12:12:31.243: [DEBUG] PluginManager::loadPlugins(): discovered plugin "AuthKeys" at "C:/Program Files/Veyon/plugins/authkeys.dll"
    2021-05-10T12:12:31.243: [DEBUG] PluginManager::loadPlugins(): discovered plugin "BuiltinUltraVncServer" at "C:/Program Files/Veyon/plugins/builtin-ultravnc-server.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "BuiltinDirectory" at "C:/Program Files/Veyon/plugins/builtindirectory.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "Config" at "C:/Program Files/Veyon/plugins/config.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "Demonstration" at "C:/Program Files/Veyon/plugins/demo.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "DesktopServices" at "C:/Program Files/Veyon/plugins/desktopservices.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "ExternalVncServer" at "C:/Program Files/Veyon/plugins/external-vnc-server.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "FileTransfer" at "C:/Program Files/Veyon/plugins/filetransfer.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "LDAP Basic" at "C:/Program Files/Veyon/plugins/ldap.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "PowerControl" at "C:/Program Files/Veyon/plugins/powercontrol.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "RemoteAccess" at "C:/Program Files/Veyon/plugins/remoteaccess.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "ScreenLock" at "C:/Program Files/Veyon/plugins/screenlock.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "Screenshot" at "C:/Program Files/Veyon/plugins/screenshot.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "ServiceControl" at "C:/Program Files/Veyon/plugins/servicecontrol.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "Shell" at "C:/Program Files/Veyon/plugins/shell.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "SystemUserGroups" at "C:/Program Files/Veyon/plugins/systemusergroups.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "TextMessage" at "C:/Program Files/Veyon/plugins/textmessage.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "UserSessionControl" at "C:/Program Files/Veyon/plugins/usersessioncontrol.dll"
    2021-05-10T12:12:31.258: [DEBUG] PluginManager::loadPlugins(): discovered plugin "WebAPI" at "C:/Program Files/Veyon/plugins/webapi.dll"
    2021-05-10T12:12:31.274: [DEBUG] VeyonCore::initSystemInfo(): "4.5.5" "201026-SPI21" "winnt" "10.0.19041" "Windows 10 (10.0)" "windows" "10"
    2021-05-10T12:12:31.274: [DEBUG] ServiceDataManager::ServiceDataManager():
    2021-05-10T12:12:31.274: [DEBUG] PlatformSessionManager::PlatformSessionManager():
    2021-05-10T12:12:31.274: [DEBUG] PlatformSessionManager::openSession(): Opening session 0 for platform session "0 (console)"
    2021-05-10T12:12:31.383: [INFO] WindowsServiceCore::manageServerForActiveConsoleSession(): Session ID changed from 4294967295 to 6
    2021-05-10T12:12:31.388: [DEBUG] WtsSessionManager::querySessionInformation(): 6 WtsSessionManager::SessionInfo::UserName "ICT SPI"
    2021-05-10T12:12:31.388: [INFO] VeyonServerProcess::start(): Starting server for WTS session 6 with user "ICT SPI"
    2021-05-10T12:12:31.388: [DEBUG] WindowsCoreFunctions::runProgramInSession(): "C:\\Program Files\\Veyon\\veyon-server.exe" () ("VEYON_SERVICE_DATA_TOKEN=b101454e331a862f8613455ea79c6057dd4fb95c67ad06173178d7850d4f23a7cacee9c4a1129295cfec4693302a55a173a22a40ac6a3470515a7e1a507114c3e79aba8aef7913dfcf53cecacb421c6e66db1e7536c55042647cf04028740215633a042d6ae4e9c46d79297bfdf99b4513599aa042b34c4d4c98de297a328ee1") 7776
    

    I'm not an expert in understanding these reports. It would be nice if someone with similar problems has found a solution.

    Details:

    • Veyon 4.5.5.0 on master and clients
    • Key authentication method (working)
    • Windows 10 Education

    Thanks already!


  • It looks like there's a problem with the Veyon Server interacting with the internal VNC server (the failed to set socket timeout(0) message is also suspicious). Did you enable multi session mode in the Service settings? If so, can you disable it? Otherwise, try to enable it for testing. Can you alternatively install UltraVNC separately and configure the Veyon Service to use an external VNC server? Just to make sure it's not a problem with the builtin UltraVNC server.

    I also wonder that the thumbnails do work and remote control isn't. Both functions use the same technique and settings for connecting to the computer. Is there any TCP connection limit configured client side?